x1, y1, x2, y2 = map(float, input().split())
d = ((x1-x2)**2 + (y1-y2)**2)**0.5
print("{:.6f}".format(d)) x1, y1, x2, y2 = map(float, input().split()) x1 map(float, input().split()) map float input().split() ().split () input split y1 x2 y2 d = ((x1-x2)**2 + (y1-y2)**2)**0.5 d ((x1-x2)**2 + (y1-y2)**2)**0.5 (x1-x2)**2 + (y1-y2)**2 (x1-x2)**2 x1-x2 x1 x2 2 (y1-y2)**2 y1-y2 y1 y2 2 0.5 print("{:.6f}".format(d)) print "{:.6f}".format(d) "{:.6f}".format "{:.6f}" format d y1, x2, y2 = map(float, input().split()) map(float, input().split()) y1 x2, y2 = map(float, input().split()) map(float, input().split()) x2 x1, y1, x2, y2 = map(float, input().split()) map(float, input().split()) x1 d = ((x1-x2)**2 + (y1-y2)**2)**0.5 ((x1-x2)**2 + (y1-y2)**2)**0.5 d y2 = map(float, input().split()) map(float, input().split()) y2
x1, y1, x2, y2 = map(float, input().split())
d = ((x1-x2)**2 + (y1-y2)**2)**0.5
print("{:.6f}".format(d))